RDA and Health

I have often wondered what exactly RDA means concerning health. Who developed it and when was it first developed?

This post is for those like me who did not know it was developed for several reasons:

There were three persons who developed RDA during World War II. The reason it was developed was due to “national defense.” The government had concerns how nutrition would affect those in the armed forces. The idea was to provide the best nutrition for not only the military but also civilian personnel. They provided a guideline called RDA — which stands for Recommended Dietary Allowances. They recommended there be a “margin of safety.” The reason was because during the war accessibility of of food was low; food was rationed out to the people. This is why a “margin of safety” was designed. The guidelines of the RDA are evaluated every five to ten years. There were additions to the guidelines that included a number of servings for each food group.

What does that all mean, since the World War II has ended? I realize every five to ten years they revise the guidelines but how does that affect people on an individual basis, I wonder? When the guidelines for the daily allowance for the intake of vitamins and minerals are based on, the quantity of each nutrient an average healthy person needs to maintain for their healthy body to function there is still a question. How is it determined when it comes quantity of nutrients? According to the RDA it is done through percentage of the proportion in nutrients’ RDA standards in food and/or supplements.

Nutrient RDA highest RDA of DRI
Vitamin A 900 μg 900 μg
Ascorbic Acid Vitamin C 60 mg 90 mg
Calcium 1000 mg 1300 mg
Iron 18 mg 18 mg
Cholecalciferol Vitamin D 400 IU (10 μg) 600 IU
Tocopherol Vitamin E 30 IU 15 mg (33 IU of synthetic)
Vitamin K 80 μg 120 μg
Thiamin Vitamin B1 1.5 mg 1.2 mg
Riboflavin Vitamin B2 1.7 mg 1.3 mg
Niacin Vitamin B3 20 mg 16 mg
Pyridoxine Vitamin B6 2 mg 1.7 mg
Folate 400 μg 400 μg
Cobalamine Vitamin B12 6 μg 2.4 μg
Biotin 300 μg 30 μg
Pantothenic acid Vitamin B5 10 mg 5 mg
Phosphorus 1000 mg 1250 mg
Iodine 150 μg 150 μg
Magnesium 400 mg 420 mg
Zinc 15 mg 11 mg
Selenium 70 μg 55 μg
Copper 2000 μg 900 μg
Manganese 2 mg 2.3 mg
Chromium 120 μg 35 μg
Molybdenum 75 μg 45 μg
Chloride 3400 mg 2300 mg

Source for chart: Wikipedia